8800GT Volt-Mod

LedHed · *Last edited by LedHed; 01-02-2008 at 08:45.*

I figured I would seperate this from the Overclocking thread just to shed some light on this:

IAX Tech 8800GT V-Mod Guide:
http://iax-tech.com/video/8800gt/8800gt01.htm

What I have gathered so far:

Quote:

Order of steps:
1.)Get all parts
2.)Measure 1k Potentiometer for correct resistance(should be about 550ohms without being adjusted, adjust for desired voltage if you get the radioshack 15 turn one, which is recommended)
3.)Solder a wire to the middle peg on the resistor
4.)Solder a wire to the end peg(peg farthest from turn screw) on the resistor
5.)Solder the wire from the end peg to the VGPU point as shown on the pictures
6.)Solder the middle peg on the resistor to the ground point as shown on the pictures
7.)Tape down the resistor to the PCB as shown on the picuture
8.)Use the points shown on the picture to check and measure the Vcore's voltage

Pictures:

Any of the red dots below will work as the VR solder pt.

(Guru3d member cowie's picture)

Picture of my volt-mod:

It has come to a census that 1.5V is the max voltage on the G92, anything more provides minimal if any benefit.

This is the VR you need:
http://www.radioshack.com/product/in...tId=2062307&cp

Please feel free to add to this thread since I haven't even attempted the mod yet. I will be shortly and I will provide pictures and results. I know cowie has some knowledge on this subject

Most of this thread is info gathered from:
http://www.xtremesystems.org/forums/...d.php?t=163929

Solderless V-Mod
http://www.xtremesystems.org/forums/...d.php?t=151983

lmimmfn · 12-18-2007, 13:26 | posts: 7,008 | Location: Ireland | User is Offline

I thought you were gonna use the step up LedHed

LedHed

I am but, I am going to wait for a while considering I have like 60 days left on my step-up. I'll volt mod this 8800GT for now and then send it in for a step-up after the New Year.

robotman · 12-18-2007, 21:06 | posts: 830 | User is Offline

i did the bios mod on mine works great im at 750/1890/1900

tucsonrider · 12-18-2007, 21:42 | posts: 277 | Location: Tucson | User is Offline

Here's a much easier and safer volt mod done by software. Adjusting the volts from 1.05 to 1.1

Not as much as a hard mod, but it can e undone, and pretty safe.

Here it is explained very well by a member at hardforums.

http://www.hardforum.com/showthread....1249339&page=2

lmimmfn · 12-19-2007, 04:05 | posts: 7,008 | Location: Ireland | User is Offline

Quote:

Originally Posted by LedHed

I am but, I am going to wait for a while considering I have like 60 days left on my step-up. I'll volt mod this 8800GT for now and then send it in for a step-up after the New Year.

Ahh ok, i would have thought there would be no way they'd allow you to step up if you start volt modding it is all, anyway id love to hear the results of volt modding it, did you read around on performance improvements afterwards?( best case scenario )

Rammstein · 12-19-2007, 04:46 | posts: 406 | Location: Germany, Munich | User is Offline

Is the more volt maybe creating any damage you can only see in 3-6 months after your running it? Im not talking about if you let it run with to high GPU temp.

cowie · 12-19-2007, 04:53 | posts: 6,231 | Location: new jersey | User is Offline

Quote:

Originally Posted by Rammstein

Is the more volt maybe creating any damage you can only see in 3-6 months after your running it? Im not talking about if you let it run with to high GPU temp.

well i will find out but remember the good thing about hard mod you can raise and lower volts at will.
jeez in summer you could lower volts a tad under stock volts to help lower temps

heres a solderless mod you just use thin wires and tape with conductive ink it looks easy e-nuff
and led you know it comes off easy too.
just remember to use the 88gt vmod point/s
http://www.xtremesystems.org/forums/...d.php?t=151983

Rammstein · 12-19-2007, 05:54 | posts: 406 | Location: Germany, Munich | User is Offline

the bios voltmod sounds much simpler.
I updated my GPU bios once to unlock sharders with X800 pro, it was really easy. Has anyone a max volt which the 8800GT should never be taken above?

LedHed

Quote:

Originally Posted by lmimmfn

Ahh ok, i would have thought there would be no way they'd allow you to step up if you start volt modding it is all, anyway id love to hear the results of volt modding it, did you read around on performance improvements afterwards?( best case scenario )

You'd actually be surprised, the volt-mod is easily reversed to stock and there is no way to tell it was done. eVGA covers after market heat sinks and overclocking, so I'm really not worried at all about the step-up after doing the mod.

Quote:

Originally Posted by cowie

heres a solderless mod you just use thin wires and tape with conductive ink it looks easy e-nuff
and led you know it comes off easy too.
just remember to use the 88gt vmod point/s
http://www.xtremesystems.org/forums/...d.php?t=151983

Thanks for that link, I'll probably use it extensively.

cowie · *Last edited by cowie; 12-19-2007 at 08:34.*

Quote:

Originally Posted by Rammstein

the bios voltmod sounds much simpler.
I updated my GPU bios once to unlock sharders with X800 pro, it was really easy. Has anyone a max volt which the 8800GT should never be taken above?

yes easy just as easy to screw up your card but everybodys different me i'll solder my card all day long but dont like to flash

i'd have to say cooling plays a big part in it but 1.25-30 should be ok.
if you have 1.20v and you idle 55c than its alot but if you 1.30 and ilde 30c and load 65c you ok

LedHed · *Last edited by LedHed; 12-19-2007 at 08:51.*

Quote:

Originally Posted by cowie

yes easy just as easy to screw up your card but everybodys different me i'll solder my card all day long but dont like to flash

i'd have to say cooling plays a big part in it but 1.25-30 should be ok.
if you have 1.20v and you idle 55c than its alot but if you 1.30 and ilde 30c and load 65c you ok

cowie, I thought everyone was at a consensus on the xtreme boards that 1.35V was the sweet spot for the G92?

(I am by no means suggesting this voltage on stock cooling)

It seems like most people on 1.35V were hitting between 800-900mhz. I saw people on the boards running 1.5V but they weren't really getting any higher than the guys with 1.35V.

Is 1.35V what I should go for considering my GPU cooling consists of Thermalright HR-03 GT + 120mm Antec TriCool Fan?

cowie · *Last edited by cowie; 12-19-2007 at 09:16.*

1.35 is ok for aftermarket cooling but if your amb. temps are like 40c in room temp i donk think 1.35 would be good.
1.35 was ok for me on modded stock cooler as a matter of fact.
but play the sweet spot thing by hear if 1.30 gets you 830 and 1.35 gets you 835.the extra .05v might not be worth it understand?
its all different even if it is the same card.you might get lucky and run 830 on 1.25v never know

if not for my benchmark habit i would have stopped at 1.28-29(800 core) in all honsesty,under 1.25 did not make my temps rise one bit.
i can not hit anything over 868 with 1.51 peak load(card will get volt spikey)1.42 idle -1.50v load.
so good luck and take it slow

LedHed

Well my room temp is 23C and I am using an Antec 900 + 120mm Thermaltake Fan (side panel) + Thermalright HR-03 GT + Antec 120mm TriCool.

I'd say cooling shouldn't be an issue for me

tucsonrider · 12-19-2007, 11:33 | posts: 277 | Location: Tucson | User is Offline

Here's the easiest, step-by-step instructions on hard-moding the volt mod complete with easy to see pics.
http://iax-tech.com/video/8800gt/8800gt01.htm

LedHed

^ great guide! thanks a ton.

cowie · 12-19-2007, 16:46 | posts: 6,231 | Location: new jersey | User is Offline

i should have taken a upclose to show removed resisters but was to lazy to take card out sry.

LedHed · *Last edited by LedHed; 12-26-2007 at 10:44.*

looks good cowie

why does my potentiometer have 3 pin connections? It looks like you just cut yours off? I heard some guys saying they have heat sinks on their VR's, do you? Also what are you talking about a removed resistor?

I'll be doing my volt-mod in a few hours when I get home, will post results tonight.

My cooling

:

tucsonrider · 12-26-2007, 12:30 | posts: 277 | Location: Tucson | User is Offline

most pots have 3 pins: input, ground, and wiper.

What you have to connect is the input (v), and ground.

On the cermet pot (radio shack 271-342), the one closest to the shaft is the wiper, middle is ground, and one farthest from the shaft is for input.

You just have to connect the input (farthest from shaft) and ground (middle).

cowie · *Last edited by cowie; 12-26-2007 at 13:00.*

yeah what he said

damn led lookin good

but remember to set vr at 1k .998
(by touching the "red" and "black" of your
ddm,to one of each remaning posts)
before you do anything, double check
soldering for me is easy and i have volt modded lots of vga's with only one "failure" do to,too mucho volts.(i got greedy with a xxx 68gs v1.79-82)still have pairs of 6,7,8 series cards ....
do it at your own risk blah blah

i'm no v-mod pro i just know enuff to do this kinda thing.
just follow pics and directions
if i have the card i do it cus stock hardware is no fun.

LedHed

Well I got it done after a few tries

That main solder point for the VR is a bitch to get to!

Cowie could you do me a favor and run 3DMark06 and monitor your voltage? When I run 3DMark my Multi Meter shows 1.28V however when it gets into a bench it bumps to 1.32V. Are you experiencing this and should I be alarmed about it?

Before 3DMark:

During 3DMark:

My temps are:

Idle: 36C
Load: 46C

810/1820/2000

tucsonrider · 12-26-2007, 20:58 | posts: 277 | Location: Tucson | User is Offline

Looks nice!

I don't know if the jump in voltage is normal or not.

Let see some benchies!

LedHed

Final clocks:

850/2000/1000

Idle: 37C Load: 51C

Time for benching.

LedHed · *Last edited by LedHed; 12-27-2007 at 00:56.*

Well 3DMark06 has me confused, check out these results:

850/2000/1000: 8862
830/1900/980: 8903
815/1850/980: 9063
805/1800/980: 9072
790/1780/980: 9052
800/1850/980: 8879
800/1800/980: 8795

I'm guessing it's my A64 causing these numbers. Considering I am gaming at 1920x1200 and 3DMark06 runs at 1280x1024 I guess I should benchmark with something at 1920x1200. Any suggestions? Crysis? BioShock? FEAR?

I just don't understand why the higher clock speeds aren't higher if I am giving it all the volts it needs and the temps are down, plus it passed ATI Tool for 2.5 mins.

I am using 1.30V and my max load temp is still 51C at all the above clock speeds.

**Edit**

I went back and used 3DMark06 Pro Edition at 1920x1200 with the rest of the settings at default:

HDR/SM3.0 Scores:

800/1800/980: 3964
820/1850/1000: 3995
835/1900/1000: 4047
850/1975/1000: 4104

so it looks like 3DMark06 at 1280x1024 isn't going to show me gains due to the CPU bottleneck at low resolutions. However since I game at 1920x1200 the above benchmarks in HDR/SM3.0 show gains. Now I need to decide on a speed combination...

cowie · *Last edited by cowie; 12-27-2007 at 02:19.*

dude you made my day!!
very nice and great results
you rig pic to me just stepped up a notch lol.

3d jump about.05 is normal (unlike g80's which vdroop at load)
seems the card is staying cool,very good.
is the shader clock topped out?high shaders=points... mostly
some games may not like the real high clocks,so play it by ear when it comes to that.
and if you push volts to high you will encounter the ovp/ocp which will bring all the fun to an end,dont worry just get volts back down(below1.35 3d)and restart .
and leave ram volts alone it wont help much.

seeing peeps doing vmods is cool

great F'N job!!